<template>

    <div class="app-container">

        <h2 style="text-align: center;">发布新课程</h2>

        <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
            <el-step title="填写课程基本信息"/>
            <el-step title="创建课程大纲"/>
            <el-step title="最终发布"/>
        </el-steps>

        <el-form label-width="120px">

            <el-form-item label="课程标题">
                <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
            </el-form-item>

            <!-- 所属分类 TODO -->
            <el-form-item label="课程分类">
                <el-select
                    v-model="courseInfo.subjectParentId"
                    placeholder="一级分类" @change="subjectLevelOneChanged">

                    <el-option
                        v-for="subject in subjectOneList"
                        :key="subject.id"
                        :label="subject.title"
                        :value="subject.id"/>

                </el-select>

                <!--二级分类-->
                <el-select v-model="courseInfo.subjectId" @change="subjectLevelTwoChanged"  placeholder="二级分类">
                    <el-option
                        v-for="subject in subjectTwoList"
                        :key="subject.id"
                        :label="subject.title"
                        :value="subject.id"/>
                </el-select>
                <!--<span>selected: {{courseInfo.subjectId}}</span>-->
            </el-form-item>


            <!-- 课程讲师 TODO -->
            <!-- 课程讲师 -->
            <el-form-item label="课程讲师">
                <el-select
                    v-model="courseInfo.teacherId"
                    placeholder="请选择">

                    <el-option
                        v-for="teacher in teacherList"
                        :key="teacher.id"
                        :label="teacher.name"
                        :value="teacher.id"/>

                </el-select>
            </el-form-item>

            <el-form-item label="总课时">
                <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right"
                                 placeholder="请填写课程的总课时数"/>
            </el-form-item>

            <!-- 课程简介 TODO -->
            <el-form-item label="课程简介">
                <tinymce :height="200" v-model="courseInfo.description"/>
            </el-form-item>


            <!-- 课程封面 TODO -->
            <!-- 课程封面-->
            <el-form-item label="课程封面">

                <el-upload
                    :show-file-list="false"
                    :on-success="handleAvatarSuccess"
                    :before-upload="beforeAvatarUpload"
                    :action="BASE_API+'/eduOss/fileOss'"
                    class="avatar-uploader">
                    <img :src="courseInfo.cover">
                </el-upload>

            </el-form-item>

            <el-form-item label="课程价格">
                <el-input-number :min="0" v-model="courseInfo.price" controls-position="right"
                                 placeholder="免费课程请设置为0元"/>
                元
            </el-form-item>

            <el-form-item>
                <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
            </el-form-item>
        </el-form>
    </div>
</template>

<script>
	import course from "@/api/edu/course";
	import subject from "@/api/edu/subject";
	import Tinymce from '@/components/Tinymce'

	export default {
		//声明组件
		components: {Tinymce},

		data() {
			return {
				saveBtnDisabled: false,
				subject: {},
				courseInfo: {
					title: '',
					subjectId: '',//二级分类id
					subjectParentId: '',//一级分类id
					teacherId: '',
					lessonNum: 0,
					description: '',
					cover: '/static/test.png',
					price: 0
				},
				BASE_API: process.env.BASE_API, // 接口API地址
				// BASE_API: "http://localhost:8002", // 接口API地址
				teacherList: [],
				subjectOneList: [],//一级分类u
				subjectTwoList: [],//二级分类
                courseId:'',
                isUpdate:false

			}
		}, watch: {
			$route(to, from) {//路由发生变化,方法执行
				this.init()
			}
		},
		created() {
            this.init()
		},
		methods: {
			subjectLevelTwoChanged(val){
				console.log(val)
                //todo
				this.courseInfo.subjectId = val
            },
			init(){
				//获取路由的id
				if (this.$route.params && this.$route.params.id) {
					this.courseId = this.$route.params.id
					this.getInfo()
                    this.isUpdate = true
				}else {
                    //清空
                    this.courseInfo = {}
					this.courseInfo.cover = '/static/test.png'
					this.getTeacherList()
					this.getOneSubject()
				}
            },
			// subjectLevelTwoChanged(val){
			// 	console.log(val)
			// 	if(val){
			// 		this.$set()
            //     }
            // },
            //课程信息回显
			getInfo(){
			    course.getInfoById(this.courseId).then(response=>{
			    	this.courseInfo = response.data.course
                    //解决二级列表无值的问题
                    //查询所有的分类
                    subject.getSubjects().then(response=>{
                    	//获取所有一级分类
                        this.subjectOneList = response.data.list

                        //遍历数组,比较当前courseInfo和一级是否相同
						for (let subject of this.subjectOneList) {

							if(this.courseInfo.subjectParentId === subject.id){
								this.subjectTwoList = subject.children
                            }
						}
                    })
                    this.getTeacherList()

                })
            },
            //获取一级分类
			getOneSubject() {
				subject.getSubjects().then(response => {
					this.subjectOneList = response.data.list
					console.log(this.subjectOneList)
				})
			},
            //获取讲师列表,回显下拉列表
			getTeacherList() {
				course.getTeacherList().then(response => {
					this.teacherList = response.data.items
				})
			},
            addCourse(){
				course.addCourseInfo(this.courseInfo).then(response => {
					//提示信息
					//提示信息
					this.$message({
						type: 'success',
						message: '添加课程信息成功!'
					});
					//跳转
					this.$router.push({
						path: '/course/chapter/' + response.data.courseId
					})

				})
            },
            updateCourse(){
				course.updateInfo(this.courseInfo).then(response => {
					//提示信息
					//提示信息
					this.$message({
						type: 'success',
						message: '修改课程信息成功!'
					});
					//跳转
					this.$router.push({
						path: '/course/chapter/' + this.courseId
					})

				})
            },
			saveOrUpdate() {

				if(this.isUpdate){
					this.updateCourse()
                }else {
					this.addCourse()
                }
			},
			//一级分类一旦改变,就改变二级分类的绑定
			subjectLevelOneChanged(value) {
				//
				for (let item of this.subjectOneList) {
					// console.log(item)
					if (item.id === value) {
						this.subjectTwoList = item.children
						this.courseInfo.subjectId = ''
						console.log(this.subjectTwoList)


					}
				}

			},
			//上传封面成功调用的方法
			handleAvatarSuccess(res, file) {
				this.courseInfo.cover = res.data.url
			},
			//上传之前调用的方法
			beforeAvatarUpload(file) {
				const isJPG = file.type === 'image/jpeg'
				const isPNG = file.type === 'image/png'
				const isLt2M = file.size / 1024 / 1024 < 2

				if (!isJPG || !isPNG) {
					this.$message.error('上传头像图片只能是 JPG 格式!')
				}
				if (!isLt2M) {
					this.$message.error('上传头像图片大小不能超过 2MB!')
				}
				return isJPG && isLt2M && isPNG
			},
		}
	}
</script>

<style scoped>
    .tinymce-container {
        line-height: 29px;
        width: 800px;
    }
</style>